So I played Stray recently, and it was a rather fun and unique game (most probably due to the fact that you are playing as a cat 
), and it reminded me of how interesting platforming games could be. You can check out my impression (and screenshots) of the game via this thread.
Though more games are becoming multiplayer-oriented, I still lean forward to singleplayer campaigns in games because of the story as well as to appreciate the world and level designs that artists, designers, and developers have poured their hearts into.
One of the games that I really like in terms of world design is the Bioshock franchise. Imagine being stranded in a city at the bottom of the ocean of which society was (or had already) fallen apart due to civil war, and having to avoid running into the people living there (who at that point were all spliced up and ready to kill you on sight) while soaking up the glorious Art Deco aesthetics.
Oh, and let’s not forget about the whole philosophy of which the city is based on - Objectivism - which I do not think I could cover completely in this topic.